3585728

Modeling degradation of paralytic shellfish toxins in freshwater systems

Date
August 22, 2021

Lyngbya wollei is a benthic cyanobacteria known to produce several acetylated analogues of the paralytic shellfish toxin saxitoxin. Infestations, or blooms, of Lyngbya wollei appear as filamentous masses attached to sediment surfaces that can persist for several years at levels of 20-30kg/m2. The associated saxitoxin analogues, known as the Lyngbya wollei toxins, or LWTs, are not as toxic as saxitoxin but typically occur in much higher concentrations. Work presented here addresses the environmental fate of the LWTs by simulating the environmental conditions of a local reservoir, Lake Wateree SC, in the laboratory. L. wollei samples were collected from multiple points in the reservoir and processed in the laboratory to quantify and qualify the LWTs present in each sample. Leaching studies were performed to determine the possibility that toxins could directly effuse from live or dead algal samples into surrounding waters. Hydrolytic degradation was determined at pH 6-10; notably the LWTs appeared to experience deacetylation to yield decarbamoyl analogues, including dcSTX, for a net increase in toxicity. The temperature dependence of hydrolysis was determined over the range 10-40 °C. A model of the varying hydrolysis rate of the LWTs is presented based on measured diel variation in pH and T in Lake Wateree at a site immediately adjacent to a microbial mat.

Related Products

Thumbnail for Neutral pH active nanozymes for sensing
Neutral pH active nanozymes for sensing
Nanozymes are functional nanomaterials with enzyme-like activities. Since they combine the advantages of artificial enzymes and functional nanomaterials, they have found wide applications ranging from bioanalysis and bioimaging to therapeutics and environmental protection…
Thumbnail for Organophosphorus hydrolase-mimicking nanozymes for hydrolysis of organophosphorus compounds
Organophosphorus hydrolase-mimicking nanozymes for hydrolysis of organophosphorus compounds
Organophosphorus compounds are known to be used as organophosphorus pesticides and nerve gases due to their infamous inhibition of acetylcholinesterase, leading to serious threats to health and environment…
Thumbnail for What happens when algae and algal toxins enter our drinking water sources? Formation of disinfection by-products during the chlorination of Lyngbya wollei, Microcystis aeruginosa, Phormidium sp., and Saxitoxin
What happens when algae and algal toxins enter our drinking water sources? Formation of disinfection by-products during the chlorination of Lyngbya wollei, Microcystis aeruginosa, Phormidium sp., and Saxitoxin
Harmful algal blooms are a major concern worldwide and are especially problematic in the United States since algae can impact drinking water treatment plants that depend on surface water sources…